Socket wrench

ABSTRACT

A socket wrench is formed as a barrel having an end in which is a circular opening. The opening is of an internal diameter approximately equal to the distance across the corners of a hexagonal nut. Said end is grooved crosswise at 120* intervals. In each groove is removably fastened a bar made of wear-resistant tool-steel bar stock of square cross section chamfered on one corner. The inner flat faces of these bars bridge across said opening for flatwise engagement with every other flat face of the hexagonal nut. The segments of said circular opening between bars extend clear of the sides of the nut which are not engaged by the bars. Under the opening and the bridging bars the barrel has an internal shoulder which is engageable with the corners of the nut to determine the axial positions of the bars on the nut. The other end of the barrel is provided with an adapter for coupling to a rotary power driving element.

United States Patent inventors :(ave A. Smith 2,405,462 8/ 1946 Stair 8 1/121X ennmgs; F A Ladendeckms" 1 012 053 4/1952 :21? P TENTS 81/12l( 1 No. 3 s u u I n t 1 a e n s Filed g 25 1 ltaly 8 l) Patented May 4, 1971 Primary Examiner-James L. Jones, Jr. Assignee McNeil Corporation Attorney-Keenig, Senninger, Powers and Leavitt Akron, Ohio SOCKET WRENCH end in wi iiiliiil igih fi iiiii 9 Drawmg nal diameter approximately equal to the distance across the US. Cl 81/121, comers of a hexagonal nut. Said end is grooved crosswise at 1/ 120 intervals. In each groove is removably fastened a bar Int. Cl 06, made of weap 'es stant toolteel bar tock of quare cross sec- F M f 1 18 l /311/20l0 tion chamfered on one corner. The inner flat faces of these 1e 10 Search bar bridge across said opening for flatwise engagement with 15 q l );2 9 /282 every other flat face of the hexagonal nut. The segments of q said circular opening between bars extend clear of the sides of References Cited the nut which are not engaged by the Under the opening UNITED STATES PATENTS and the bndglng bars the barrel ha: an lnternal shoulder wh1ch is engageable with the corners o the nut to determine the 2,832,395 4/ 1958 Fisher 269/282X axial positions of the bars on the nut. The other end of the bar- 1,832,185 1 1/ 1931 Cochrane 81/121-1 rel is provided with an adapter for coupling to a rotary power 1/1963 Beers 81/121 driving element.

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Patented May 4, 1971 2 Sheets-Sheet 1 Patented May 4, 1971 2 Sheetsheot 2 & L (N SOCKET WRENCH BACKGROUND OF THE INVENTION Power-driven socket wrenches such as used on manufacturing assembly lines and the like are subject to hard wear and abuse. Under some not unusual conditions they will last only a day or so of continuous assembly line operations. This is because an operator applies the wrench to nuts while its power driving tool is turning. With the usual six-sided engagement between a conventional hexagonal socket wrench and the six faces of a hexagonal nut there are six possibilities on every turn of interference and. a hang-up at an outside dihedral comer of the nut and an inside dihedral corner of the socket. This results in the socket spinning on the nut without effecting prompt driving engagement when the socket is thrust axially against it. The excessive spinning between engagements and under axial pressure causes excessive wear on the socket so that its hexagonal form is soon damaged. This is particularly true when the sockets, as is ordinarily the case, are made of easily machinable material such as cold-rolled steel whichis not greatly wear-resistant. The delay in effecting engagements also slows assembly line operations. Moreover. once the engaging surfaces of former types of socket wrenches became damaged, they were not repairable and an entire new socket head was demanded.

SUMMARY OF THE INVENTION According to the invention, a conveniently machinable receive an adapter for making connection with a driver; or, the adapter may be omitted and the head machined to receive the driver directly. At an axially flanged nut-receiving end of the head three replaceable bars of chamfered tool-steel bar stock are arranged for flatwise engagement at l20 intervals along contact areas on three sides of a nut, rather than sixsided contacts on six sides thereof as-heretofore. The bars are composed of more difficult to machine tool-steel bar stock, but requiring only a few simple machining operations. The bars form bridges across the axially flanged end of the head. Thus the inside portions of the flange between the tool-steel bars are in the form of circular segments spaced from the three sides of the nut not engaged by the bars. Because of this there is avoided the need for critical registration of former male and female dihedral comer portions of socket and the nut corners in order to effect axial engagement, such as heretofore encouraged considerable spin and wear of a socket on nuts between successive engagements.

BRIEF DESCRIPTION OF THE DRAWINGS Referring now to the drawings,

FIG. I is a side elevation of the wrench;

FIG. 2 is a right-end view of FIG. 1;

FIG. 3 is a left-end view of FIG. 1;

FIG. 4 is a vertical axial section taken on line 4-4 of FIG. 2, the dotted lines outlining a nut as engaged by the wrench;

FIG. 5 is an enlarged end view like FIG. 2 and illustrating application tothe nut shown in solid lines; and

FIG. 6 is a detail section taken on line 6-6 of FIG. 2.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, numeral 1 indicates a barrel formed of easily machinable material such as cold-rolled steel. This has a first end bore 3 which terminates in an internal stop-forming shoulder 5 and provides an axial directed end flange 7. The diameter of the first bore 3 in flange 7 is approxi mately equal to the distance across corners of a hexagonal nut 9 to be received in the end flange 7 (see FIG. 5). The comers of the nut come into engagement with the stop-forming shoulder 5.

The barrel is further made with a second bore as shown at 11 which reaches from the shoulders 5 to a second shoulder 13. From the second shoulder 13 to the other end of the barrel is a third bore 15 which extends through a reduced end 17 of the barrel 1. In the bore 15 is an adapter 19 held in place by setscrews 2]. The adapter 19 includes a square hole 23 for the reception of the usual square driving endpiece 25 of a rotary power driving tool (not shown).

The piece 25 includes a conventional spring-pressed locking detent button 27. A hole 29 is employed in the adapter 19 for receiving this detent button when the square endpiece 25 of the driving tool is pushed into the square hole 23. A shoulder between the square hole 23 and a bore 31 in the adapter determines axially how far the square end piece 25 may be pushed into the adapter to register the button 27 with hole 29. Another hole 33 is formed in the reduced portion 17 of the barrel 1 registering with hole 29 so that-the button27 may be reached by a drive pin or the like to force it back for release 0 the piece 25 from the adapter 19.

Milled across the flange 7 at intervals are slots 35 of approximately square cross section for receiving bars 37 of a highly wear-resistant material such as tool steel. The bars 37 are also of approximately the same square cross section to interfit snugly but removably within the slots 35. The ends 39 of the bars 37 are rounded as shown. The slots 35 are so positioned that thebars 37 form bridges over the shoulder 5. The planes of the inner surfaces 41 of the bars are about tangent to the cylinder of bore 11 extended as shown in FIG. 5. Thus the inner surfaces of the bridging portions of the bars 37 are designed for flatwise engagement of three alternate faces of the hexagonal nut 9 When the latter enters the flange 7. This leaves three circular segments 43 of the flange 7 which advantageously clear the other three sides of the nut9.

A conventional socket wrench which registers and engages with all six sides of a hexagonal nut has six female dihedral angles conjugately engaging the six male dihedral angles at the corners of a contained nutsuch as 9 (see the angle C on FIG. 5). The closer and better that such a wrench. fits a nut the more difficult it is to accomplish prompt registry while the wrench is rotating. An operator's normal tendency to increase axial pressure to bring about quick engagement only aggravates the difficulty and is self-defeating. This results in time delay in making connections and wear on the socket as it spins on a nut prior to forming a connection under axial pressure.

By means of the invention, the above-mentioned difficulties are avoided because the arcs 43 between bars 37 obviate any female dihedral angles in the socket for interfitting such with any male dihedral corner angles of the nut. In otherwords, tangent planes to the arcuate surfaces 43 where they meet the bars 37 at the corners of the nut are at larger angles relative to the inner planes of the bars than the dihedral comer angles of the nut. As a result, the wrench will quickly and accurately engage three sides of a nut under any of various axial pressures and with minimum spin and wear. A small chamfer 42 of the comers of the bars 37 where they first engage a nut further facilitates the prompt engagement. Moreover, the bars, being made of tool steel, in and of themselves strongly resist wear. Each bar is held fast but removably in its slots by Allen-head screws 45 extending through holes in the bars and threaded into the flange 7 (see FIG. 6). Thus one or more bar may be replaced if and when worn by long use. Machining operations required on the bar stock are minimal.

In operation an operator moves the barrel axially toward a nut hand-started on a screw (not shown). The bars 7 contact the conventionally chamfered top of the nut. The barrel is rotated as it is pressed toward the nut. Under axial pressure the bars 37 first engage the conventional chamfer on the top of the nut and then quickly engage on alternate sides of the nut. The nut then advances on the threads of the screw which carries it. The distance that the bars slide axially along the three faces of the nut is determined by the engagement of the outer end of the nut with the shoulder 5. The bars are preferably made axially thinner than the thickness of the nut as indicated on FIG. 4, wherein dotted lines outline the nut 9. Quick engagement is due first to the absence of the requirement that any female dihedral angle such as C on the wrench shall conjugately engage any male dihedral corner angle of the nut; second to there being only a three-, rather than a six-face engagement to be made; and third to the bar chamfers. As the nut advances in engagement with the screw, the end of the latter is accepted in the bore 11. After the nut has been finally set, disconnection is accomplished simply by retracting the piece 25 with barrel 1.

As shown in the drawings, the bars 37 are thinner than the conventional nut. Hence when the corners of the nut engage the shoulder 5 the bars 37 are positioned between the ends of the nut when engaged therewith.

ln view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above construction or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. A socket wrench comprising a barrel having an axially directed nut-receiving opening therein at one end for the reception of a hexagonal nut, slots formed at l intervals across the open end of the barrel, bars in said slots bridging across said opening to engage three alternate sides of the nut when received in said opening, parts of the opening substantially clearing the alternate three sides of said nut which are not engaged by said bars.

2. A wrench according to claim 1, wherein said barrel is made of conveniently machinable metal, said bars being made of comparatively hard and wear-resistant metal, and quick detachable connections for said bars in their slots.

3. A wrench according to claim 2, including a shoulder within the barrel underlying the bridging portions of the bars for determining the axial position of the nut in the barrel when its said three sides are engaged by the bars, said bars being thinner than the nut in an axial direction, whereby said thinner bars engage between the ends of the nut when the nut engages said shoulder.

4. A socket wrench comprising a barrel having an axially directed end portion forming an internal nut-receiving cylindrical opening therein for the reception of a hexagonal nut, the inside diameter of said cylindrical opening approximating the dimension of the nut across its corners, slots formed at I20 intervals across said end portion, bars nested in said slots and having portions bridging across said opening to engage three alternate sides of the nut when recieved in said opening, circular segments of the inside of said cylindrical opening between the bars substantially clearing the alternate three sides of said nut which are not engaged by said bars.

5. A socket wrench according to claim 4, wherein the bars are axially thinner than the nut and the barrel includes an internal shoulder underlying the bridging portions of said bars for engagement of the nut at its corners, whereby the axial locations of the bars relative to the nut are located between its end when the wrench and the nut are engaged.

6. A socket wrench according to claim 5, wherein said bars are axially thinner than the nut.

7. A socket wrench according to claim 6 wherein the other end of the barrel is provided with a bushing for forming a quick-attachable and quick-detachable connection with a driving tool element.

8. A socket wrench according to claim 7 wherein the barrel is made of comparatively easily machinable metal and said bars are composed of tool-steel stock.

9. A socket wrench according to claim 8 wherein said bars are held in their respective grooves by quick-detachable connections. 

1. A socket wrench comprising a barrel having an axially directed nut-receiving opening therein at one end for the reception of a hexagonal nut, slots formed at 120* intervals across the open end of the barrel, bars in said slots bridging across said opening to engage three alternate sides of the nut when received in said opening, parts of the opening substantially clearing the alternate three sides of said nut which are not engaged by said bars.
 2. A wrench according to claim 1, wherein said barrel is made of conveniently machinable metal, said bars being made of comparatively hard and wear-resistant metal, and quick-detachable connections for said bars in their slots.
 3. A wrench according to claim 2, including a shoulder within the barrel underlying the bridging portions of the bars for determining the axial position of the nut in the barrel when its said three sides are engaged by the bars, said bars being thinner than the nut in an axial direction, whereby said thinner bars engAge between the ends of the nut when the nut engages said shoulder.
 4. A socket wrench comprising a barrel having an axially directed end portion forming an internal nut-receiving cylindrical opening therein for the reception of a hexagonal nut, the inside diameter of said cylindrical opening approximating the dimension of the nut across its corners, slots formed at 120* intervals across said end portion, bars nested in said slots and having portions bridging across said opening to engage three alternate sides of the nut when recieved in said opening, circular segments of the inside of said cylindrical opening between the bars substantially clearing the alternate three sides of said nut which are not engaged by said bars.
 5. A socket wrench according to claim 4, wherein the bars are axially thinner than the nut and the barrel includes an internal shoulder underlying the bridging portions of said bars for engagement of the nut at its corners, whereby the axial locations of the bars relative to the nut are located between its end when the wrench and the nut are engaged.
 6. A socket wrench according to claim 5, wherein said bars are axially thinner than the nut.
 7. A socket wrench according to claim 6 wherein the other end of the barrel is provided with a bushing for forming a quick-attachable and quick-detachable connection with a driving tool element.
 8. A socket wrench according to claim 7 wherein the barrel is made of comparatively easily machinable metal and said bars are composed of tool-steel stock.
 9. A socket wrench according to claim 8 wherein said bars are held in their respective grooves by quick-detachable connections. 